Through two linked applications, this R34 would support: a) collaboration/partnership between a psychotherapy expert (Jarrett) and a perinatal specialist (Brandon) located in an academic medical center, and an expert in web-based education (Shanahan) in the private sector; b) development of an innovative, preemptive, preventive strategy for women at risk for major depressive disorder (MDD) who are planning to conceive or who are within the first 56 days of pregnancy; and c) evaluation of the safety, tolerability, acceptability, and feasibility of the intervention. We propose to initiate a program of research that has the potential to transform the evidence-based choices, access, and uptake of practices available to women with MDD during pregnancy planning and the perinatal period, when they are at high risk for depressive relapse and recurrence. Early innovative, developmental efforts are necessary to provide a proof-of-concept as a prerequisite to future, formal tests in this population, which is often underrepresented in clinical trials. Risk is defined by current remission of MDD and at least one previous episode of definite MDD. We will develop a web-assisted intervention, Preventive Cognitive Therapy (P-CT), to prevent or reduce relapse/recurrence from conception planning through delivery and postpartum. We will also create a Clinician-Assisted Internet Monitoring (C-AIM) system for monitoring depressive symptoms. This R34 and the associated emerging research program address the NIMH priorities to: 1. Develop new and better interventions that incorporate the diverse needs and circumstances of people with mental illnesses. Vulnerable women planning to conceive have limited choices in order to reduce their risk; this research seeks to increase their evidence-based choices by developing P-CT to address the needs of at-risk women. The NIMH has called for studies to address the expansion of existing interventions and treatment development for perinatal mental health problems as described in PA09-174. 2. Chart mental illness trajectories to determine when, where, and how to intervene. We will chart the trajectory of MDD during the perinatal period and provide initial hypotheses on when, where, and how to intervene. Clinician-Assisted Internet Monitoring is designed to promote early detection of MDD, thereby increasing the safety of watchful waiting during and after antidepressant medication withdrawal or avoidance. 3. Strengthen the public health impact of NIMH-supported research. Moving perinatal mental health research findings from the academic setting into real-world practice is a public health priority. Using clinician-assisted Internet monitoring of symptoms and web-based preventive psychotherapy in at-risk groups has the potential to increase the availability of care, as well as the potential for dissemination into primary care settings. We predict that both P-CT and C-AIM can be integrated within primary care community clinics, if these constituencies are included in development and contingent upon successful tests of effectiveness.